This invention relates to apparatus for unlatching power door locks and lowering power windows of a motor vehicle in emergency situations. More particularly, the present invention relates to emergency vehicle exit systems having sensor-diagnostic circuits to periodically verify the integrity of the condition sensors thereof.
Since about the mid 1980s, an increasing number of motor vehicles have been equipped with power windows and power door locks. Once considered optional accessories, these features are now installed in a majority of all new motor vehicles. Generally, the power window feature is operational only when the key is set in the run position and the accessories are receiving power from the battery. The power door locks are operational, regardless of the ignition key""s position, as long as the motor vehicle is receiving power from the battery.
As a result of the installation of power windows and power door locks in most automobiles, two new safety hazards now exist. Firstly, in the event of an accident resulting in the incapacitation of the vehicle""s electrical power system, the conscious motor vehicle operator is often unable to open the doors or lower the windows. In many cases, there are structural damages to the door frames or to the door posts which are significant enough to prevent the manual opening of the doors from the inside. In the past, the only remedy for this situation was the breaking of a window from the inside, which was only possible when the proper tool was accessible inside the vehicle.
Secondly, in the event of an accident which results in the physical incapacitation or loss of consciousness of the vehicle operator or a passenger, there could be no able person inside the vehicle to unlock the doors or lower the windows. This represents a serious safety concern for the rescue personnel wanting to access the injured persons. In the past, the only remedy was the manual breaking of a window from the outside or the use of the Jaws of Life(trademark). However, the breaking of a motor vehicle window from the outside is likely to project shattering glass inside the vehicle, which could worsen fresh injuries on the occupants, or further harm the occupants.
These two safety concerns, basically, have created a need for emergency vehicle exit apparatus to automatically take control of the power door locks and power windows of a vehicle in emergency situations.
An apparatus for unlatching power door locks and lowering power windows generally comprises an electronic module and a plurality of condition sensors mounted at various strategic locations on the vehicle body. When these condition sensors and the wiring between the sensors and the electronic module are exposed to the weather, to vibration and to road splashes, deterioration of the sensors and wiring could occur. Therefore, a preferred feature in such emergency vehicle exit system is the provision of a circuit to periodically test the conditions of the sensors and the associated wiring, in order to detect and quickly repair a defective function of the system.
In that respect, it is believed that when an emergency vehicle exit system is equipped with one or more vehicle immersion sensors, these sensors are most vulnerable to deterioration for being continuously exposed to the weather conditions. Therefore another preferred feature of such system is that the immersion sensors must be reliable, durable and suitable for being interrogated by a sensor-diagnostic circuit.
Examples of vehicle exit systems available in the prior art to unlatch power door locks and lower power windows after an accident are described in the following documents:
U.S. Pat. No. 4,381,829 issued on May 3, 1983 to B. Montaron;
U.S. Pat. No. 4,785,907 issued on Nov. 22, 1988 to K Aoki et al.
U.S. Pat. No. 5,327,990 issued on Jul. 12, 1994 to A. B. Busquets;
U.S. Pat. No. 5,547,208 issued on Aug. 20, 1996 to J W Chappell et al.
U.S. Pat. No. 5,574,315 issued on Nov. 12, 1996 to H J Weber;
Although several vehicle emergency exit systems are available in the prior art, it is believed that these prior systems are deficient in at least the features of having immersion sensors that are resistant to the weather conditions and having immersion sensors that are capable of being interrogated by a diagnostic circuit. As such, it is believed that a need still exists for a system in which the conditions sensors are more durable and reliable than the prior art detectors. Furthermore, it is also believed that a need exists for an emergency vehicle exit system which has means to periodically verify the conditions of the sensors that are exposed to rude environment and warn the vehicle operator of these conditions.
The rescue assist safety system according to the present invention, hereinafter referred to as the RAS system, is designed to provide an immediate and visible escape route out of a damaged vehicle, and to provide easier access to passengers by medical and rescue personnel. The RAS system is designed to be installed in new vehicles at the factory, or to be installed as a retrofit accessory in older vehicles, by licensed auto-mechanics.
In a broad aspect of the present invention, there is provided a system for automatically lowering power windows and unlatching power door locks of a motor vehicle in the event of an accident. The system comprises a circuit having relays for actuating the power door locks and the window lowering motors of the motor vehicle. The RAS system also comprises;
a) a vehicle immersion sensor connected to the circuit and having means to operate the relays immediately upon being exposed to a vehicle immersion condition;
b) a vehicle fire detector connected to the circuit and having means to operate the relays immediately upon being exposed to a vehicle fire condition;
c) a vehicle inversion detection switch connected to the circuit and having means to operate the relays after a set delay from being exposed to a vehicle inversion condition; and
d) a combination of a vehicle impact detection switch connected to the circuit, and a timer connected to the circuit and to the vehicle impact detection switch for operating the relays after a fixed delay upon the vehicle impact detection switch being exposed to a vehicle impact condition.
The present invention is advantageous for preventing the entrapment of people in a damaged vehicle, in four of the worst life-endangering situations, without affecting the retention of these people inside the vehicle during the development of the accidents preceding these situations.
In another aspect of the present invention, the RAS system comprises a means for interrogating some of the hazardous condition sensors, for the purpose of periodically verifying the integrity of these sensors. This feature is appreciable for ensuring a proper operation of the sensors that are exposed to rude environmental conditions, outside or under an automobile body for example.
In accordance with another aspect of the present invention, the impact detection switch is made of a hollow metal housing having a hole there though and a spring wire extending through that hole. The metal housing and the spring wire are respectively connected to an input and an output of this impact detection switch. An impact of a predetermined magnitude on the switch deflects the spring wire and momentary closes the switch for activating the RAS system. This novel impact detection switch is manufacturable in a miniature format for mounting directly on a printed circuit board.
In yet another aspect of the present invention, the vehicle inversion detection switch comprises a metal cup connected to a first part of the circuit, a metal cone mounted inside the cup in a spaced-apart relationship with the metal cup, and being connected to a second part of the circuit, and a metal ball movably held inside the metal cup, between the metal cup and the metal cone. The metal cup and the metal cone jointly define a circular hollow segment of revolution having converging surfaces defining a first gap being larger than a diameter of the metal ball and a second gap being smaller than the diameter of the metal ball. When the switch is tilted on its side or inverted upside down, the metal ball moves between the first gap and across the second gap to connect the first and second parts of the circuit. In the preferred configuration, the metal cup contains a viscous insulating fluid for dampening a motion of the metal ball between the first gap and the second gap.
This inversion detection switch is advantageous for having a built-in timer for retarding the operation of the RAS system upon being moved in a tilted or an inverted position. This switch is also advantageous for being manufacturable in a miniature format for mounting directly on a printed circuit board.
In yet a further aspect of the present invention, the immersion sensor comprises a diode mounted in a reversed biased mode and having bare lead wires which can be shorted across when immersed in water. The diode is enclosed in a perforated splash guard to prevent a false short circuit signal when the vehicle is driving through a puddle or in rain. This type of immersion sensor is advantageous for its simplicity, for its low cost of manufacture and especially for its ability to be interrogated by a diagnostic circuit, for the purpose of testing its condition.
Other advantages and novel features of the present invention will become apparent from the following detailed description.